Creep is an important characteristic of near space aerostat′ s envelope material. A creep test bench was designed to test the creep characteristics of a typical envelope material for near space aerostat, and the creep data of the material at atmospheric temperature were obtained. Based on the creep model of general polymer materials and the creep data obtained from the test, the creep calculation model of aerostat materials was analyzed, and the relevant parameters were fixed. Also, the creep variables of aerostat materials were simulated with the method of finite element analysis. Furthermore, the veracity of the creep model and the simulation analysis for DPE-3 thin film was verified by comparing the creep variables calculated by the creep model, the creep variables analyzed by the finite element simulation and the actual creep variables were obtained by the creep test. The creep test method and the results of calculation and analysis can provide a reference for the design and analysis of aerostat in near space.